U.S. Pat. No. 6,391,076, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a full flow fluid filter having a housing extending axially along an axis, and a pleated filter element having a plurality of pleats in a closed loop annulus having an outer perimeter defined by a plurality of outer pleat tips, an inner perimeter defined by a plurality of inner pleat tips, and a hollow interior extending along the axis. Fluid flows substantially directly axially through the filter element, with minimal bending and change of direction, minimizing flow restriction.
U.S. Patent Publication No. 2006/0065592, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a direct flow filter having seal tips alternately sealing upstream and/or downstream ends of wall segments to each other to define first and second sets of flow channels and protecting the ends of the wall segments from damage, including upstream ends from incoming debris, and providing structural support withstanding high flow rates and improving flow by means of the geometry of the seal.
U.S. Pat. No. 7,314,558, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a pleated panel fluid filter filtering fluid flowing along an axial flow direction and includes angled panels and/or progressively increasing flow channel width and/or skewed panel projections and/or flattened pleat tip bend lines.
U.S. Pat. No. 7,323,106, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a filter with multiple pleated filter elements having axially extending channels having a transverse pleat channel height and a lateral channel width. The pleated filter elements have different channel heights.
U.S. Pat. No. 7,540,895, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a filter including a housing with multiple flow passages and filter elements, including at least first and second flow passages therethrough including respective first and second filter elements in parallel. Respective internal dividing walls separate flow passages in space saving relation.
U.S. Patent Publication No. 2008/0011673, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a direct flow filter having one or more upstream and/or downstream face seals transversely spanning from one set of pleat tips at least partially towards the other set of pleat tips and laterally spanning adjacent channels.
U.S. Pat. No. 7,879,125, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a filter provided by pleated filter media having a plurality of pleats defined by wall segments extending axially along an axial direction along an axis and extending transversely along a transverse direction between first and second sets of pleat tips at first and second sets of axially extending bend lines. The pleated filter media spans laterally along a lateral span along a lateral direction, with the wall segments being spaced from each other by lateral gaps. The pleats have a pleat depth along the transverse direction along the wall segments between the first and second sets of pleat tips. The pleat depth varies as the pleated filter media spans laterally along the lateral direction.
U.S. patent application Ser. No. 13/002,863, filed Jan. 6, 2011, the disclosure of which is hereby incorporated herein by reference in entirety, discloses a filter assembly, panel filter element, and servicing method for reducing inlet flow restriction from a housing inlet into an inlet plenum and reducing outlet flow restriction from an outlet plenum to a housing outlet.